It's one of the touchiest questions in video and few
people bother to ask it: How long does a videocassette last? Most of us operate on the
assumption that the tapes we record today will playback far into the future. But how long
can we expect that tape to reliably store and recall our memories?

The answer is not found in advertisements for video
tape. But the truth is, unfortunately, that video tape is not forever. Unlike movie film
-- which can last for decades -- video tape is far more fragile. In fact, no magnetic
recording medium is permanent. Those ribbons of cobalt ferric oxide or metallic particles
inside the plastic shell of a videocassette represent very new technology. Even
professionals have had only 20 years of experience with traditional oxide tapes, and the
newer metal tape, introduced with the Video 8 format in 1985, is still an infant.

So, how long does a videocassette last?
Traditionally, tape manufacturers have waffled on the question. Consumers have been
offered some general storage tips (like don't leave a cassette on a car seat in the summer
sun) and assurances that the subject is not a matter for serious concern.

But now, thanks to an internal study by Sony in
Japan, a tape manufacturer has gone on the record with a specific estimate on the life
expectancy of its video tape products that should shatter any illusions that video is
forever.

Sony's research, which applies to both consumer and
professional grades of video tape, was conducted in Japan with the company's broadcast
Betacam system, the only video recording format that can use either oxide or metal tape
formulations. One of the purposes of the study, Sony noted, was to compare the longevity
of the newer metal tape against traditional oxide formulations.

The durability of both types of tape (which covers
the spectrum from brand name bargain tapes sold in supermarkets to high performance
premium cassettes) was extensively tested by Sony in environmental chambers at varying
temperature and humidity levels. The researchers wanted to find out how environmental
conditions affected key performance parameters. In order to see how wear and tear affected
tape, Sony ran cassettes through 500 playback and rewind cycles at a slow 1/30 speed on a
VCR.

The results, according to the Sony study, is that
both metal and oxide tape, when stored under environmental conditions of 77 relative
humidity "are very stable and have no change in video electromagnetic
performance."

The Sony report concluded that the life expectancy
of any tape depends on disintegration of it's chemical components, such as plastic base
film, binder polymers, back-coating materials and lubricants. Heat and moisture accelerate
the breakdown of these organic materials in all tape formulations, the report said.

So what's the bottom line. How long does Sony tell
us we can expect a videocassette to last? Since environmental conditions are the key to
the tape's chemical stability, the answer is based on storage conditions. If the user
keeps tapes at a constant temperature of 59 degrees and a relative humidity level of 40 to
60 percent, Sony predicts all modern tape formulations will last 15 years without
significant degradation.

It is important here to note the word
"constant" when speaking of the environmental conditions in which tapes are
stored. Sony recommends there be little fluctuation in temperature or humidity to prevent
expansion and contraction of the base film. Since most of us don't occupy such ideal
temperature and humidity-controlled environments at home, the 15 year figure is
unrealistic for the average consumer.

For important, irreplaceable tapes, Sony tape
product manager Les Burger recommends that consumers follow the practice of many
professional video producers and make protection copies from the master tape every three
to five years. These copies, though down a generation, at least provide insurance against
any deterioration or failure of the original master. Burger also recommends winding
important tapes at least one a year.

When a tape is so valuable that money is no object
for its protection, the ultimate in archival preservation is to make a digital backup copy
at a professional video facility. By copying a VHS or Video 8 tape to a professional
digital format, there will be virtually no loss of image quality when future copies are
made. But be prepared for to pay top dollar for this protection. Whites Photography
charges $290 per hour to transfer consumer formats to the professional D-2 format. And
that price does not include a one-hour D-2 cassette, which costs an additional $268.

The next time a friend or family member tells you
they are video taping an event for future generations to enjoy, tell them about the Sony
study. Video is not forever. Such knowledge can save a lot of disappointment later on.